Develop the first python client test application by Paho mqtt

Develop the first python client application by Paho

I. Purpose:

1. Try to send messages between 2 clients via MQTT protocol. Then, we will create 2 clients:

- One for publishing (or send) the message. Other for subscribing (or receive message).

II. Pre-condition:

- You already installed Mosquitto broker, Python.

III. Step by step

1. Download example from Github

https://github.com/eclipse/paho.mqtt.python

2. Modify subscriber(client) source

In folder example/client_sub.py. Modify some pieces of source code.

before

mqttc.connect("mqtt.eclipse.org", 1883, 60)

mqttc.subscribe("$SYS/#", 0)

after

mqttc.connect("192.168.203.76", 1883, 60)

mqttc.subscribe("test/topic1", 0)

note:

"192.168.203.76": IP address of machine which Mosquito broker installed on.

1883: mqtt port

3. Modify publisher(client) source

In folder example/publish_single.py.

before:

publish.single("paho/test/single", "boo", hostname="mqtt.eclipse.org")

after:

publish.single("test/topic1", "Let's make your passion great again", hostname="192.168.203.76")

4. Start broker

Open a command prompt and type the following text:

mosquitto -p 1883

5. Start subscriber

Open the second command prompt and go to example directory by "cd" command:

cd D:\paho.mqtt.python-master\paho.mqtt.python-master\examples

python client_sub.py

6. Start publisher to send the very first message

Open the third command prompt and type:

python publish_single.py

7. Look at the second command prompt to check the received message.

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